This module implements the so-called ISAAC algorithm, which was proposed by Robert Jenkins in 1996. The feature of the ISAAC is, when all is said, so fast compared with other pseudorandom number generators.
I don't doubt that the module implements the algorithm safely and completely as well as its pure perl version, Math::Random::ISAAC. All the same, all you have to take care is that the secure seed remains to be adequately selected on your own account.